Creep deformation and buttressing capacity of damaged ice shelves: theory and application to Larsen C ice shelf
Around the perimeter of Antarctica, much of the ice sheet discharges to the ocean through floating ice shelves. The buttressing provided by ice shelves is critical for modulating the flux of ice into the ocean, and the presently observed thinning of ice shelves is believed to be reducing their buttr...
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2013
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ftdoajarticles:oai:doaj.org/article:d7f9ce2590bb4f81863e552dfae31e08 2023-05-15T13:55:29+02:00 Creep deformation and buttressing capacity of damaged ice shelves: theory and application to Larsen C ice shelf C. P. Borstad E. Rignot J. Mouginot M. P. Schodlok 2013-12-01T00:00:00Z https://doi.org/10.5194/tc-7-1931-2013 https://doaj.org/article/d7f9ce2590bb4f81863e552dfae31e08 EN eng Copernicus Publications http://www.the-cryosphere.net/7/1931/2013/tc-7-1931-2013.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-7-1931-2013 https://doaj.org/article/d7f9ce2590bb4f81863e552dfae31e08 The Cryosphere, Vol 7, Iss 6, Pp 1931-1947 (2013) Environmental sciences GE1-350 Geology QE1-996.5 article 2013 ftdoajarticles https://doi.org/10.5194/tc-7-1931-2013 2022-12-31T07:25:10Z Around the perimeter of Antarctica, much of the ice sheet discharges to the ocean through floating ice shelves. The buttressing provided by ice shelves is critical for modulating the flux of ice into the ocean, and the presently observed thinning of ice shelves is believed to be reducing their buttressing capacity and contributing to the acceleration and thinning of the grounded ice sheet. However, relatively little attention has been paid to the role that fractures play in the ability of ice shelves to sustain and transmit buttressing stresses. Here, we present a new framework for quantifying the role that fractures play in the creep deformation and buttressing capacity of ice shelves. We apply principles of continuum damage mechanics to derive a new analytical relation for the creep of an ice shelf that accounts for the softening influence of fractures on longitudinal deformation using a state damage variable. We use this new analytical relation, combined with a temperature calculation for the ice, to partition an inverse method solution for ice shelf rigidity into independent solutions for softening damage and stabilizing backstress. Using this new approach, field and remote sensing data can be utilized to monitor the structural integrity of ice shelves, their ability to buttress the flow of ice at the grounding line, and thus their indirect contribution to ice sheet mass balance and global sea level. We apply this technique to the Larsen C ice shelf using remote sensing and Operation IceBridge data, finding damage in areas with known crevasses and rifts. Backstress is highest near the grounding line and upstream of ice rises, in agreement with patterns observed on other ice shelves. The ice in contact with the Bawden ice rise is weakened by fractures, and additional damage or thinning in this area could diminish the backstress transmitted upstream. We model the consequences for the ice shelf if it loses contact with this small ice rise, finding that flow speeds would increase by 25% or more over an area the ... Article in Journal/Newspaper Antarc* Antarctica Ice Sheet Ice Shelf Ice Shelves The Cryosphere Directory of Open Access Journals: DOAJ Articles Bawden Ice Rise ENVELOPE(-60.155,-60.155,-66.858,-66.858) Buttress ENVELOPE(-57.083,-57.083,-63.550,-63.550) The Cryosphere 7 6 1931 1947 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 C. P. Borstad E. Rignot J. Mouginot M. P. Schodlok Creep deformation and buttressing capacity of damaged ice shelves: theory and application to Larsen C ice shelf |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Around the perimeter of Antarctica, much of the ice sheet discharges to the ocean through floating ice shelves. The buttressing provided by ice shelves is critical for modulating the flux of ice into the ocean, and the presently observed thinning of ice shelves is believed to be reducing their buttressing capacity and contributing to the acceleration and thinning of the grounded ice sheet. However, relatively little attention has been paid to the role that fractures play in the ability of ice shelves to sustain and transmit buttressing stresses. Here, we present a new framework for quantifying the role that fractures play in the creep deformation and buttressing capacity of ice shelves. We apply principles of continuum damage mechanics to derive a new analytical relation for the creep of an ice shelf that accounts for the softening influence of fractures on longitudinal deformation using a state damage variable. We use this new analytical relation, combined with a temperature calculation for the ice, to partition an inverse method solution for ice shelf rigidity into independent solutions for softening damage and stabilizing backstress. Using this new approach, field and remote sensing data can be utilized to monitor the structural integrity of ice shelves, their ability to buttress the flow of ice at the grounding line, and thus their indirect contribution to ice sheet mass balance and global sea level. We apply this technique to the Larsen C ice shelf using remote sensing and Operation IceBridge data, finding damage in areas with known crevasses and rifts. Backstress is highest near the grounding line and upstream of ice rises, in agreement with patterns observed on other ice shelves. The ice in contact with the Bawden ice rise is weakened by fractures, and additional damage or thinning in this area could diminish the backstress transmitted upstream. We model the consequences for the ice shelf if it loses contact with this small ice rise, finding that flow speeds would increase by 25% or more over an area the ... |
format |
Article in Journal/Newspaper |
author |
C. P. Borstad E. Rignot J. Mouginot M. P. Schodlok |
author_facet |
C. P. Borstad E. Rignot J. Mouginot M. P. Schodlok |
author_sort |
C. P. Borstad |
title |
Creep deformation and buttressing capacity of damaged ice shelves: theory and application to Larsen C ice shelf |
title_short |
Creep deformation and buttressing capacity of damaged ice shelves: theory and application to Larsen C ice shelf |
title_full |
Creep deformation and buttressing capacity of damaged ice shelves: theory and application to Larsen C ice shelf |
title_fullStr |
Creep deformation and buttressing capacity of damaged ice shelves: theory and application to Larsen C ice shelf |
title_full_unstemmed |
Creep deformation and buttressing capacity of damaged ice shelves: theory and application to Larsen C ice shelf |
title_sort |
creep deformation and buttressing capacity of damaged ice shelves: theory and application to larsen c ice shelf |
publisher |
Copernicus Publications |
publishDate |
2013 |
url |
https://doi.org/10.5194/tc-7-1931-2013 https://doaj.org/article/d7f9ce2590bb4f81863e552dfae31e08 |
long_lat |
ENVELOPE(-60.155,-60.155,-66.858,-66.858) ENVELOPE(-57.083,-57.083,-63.550,-63.550) |
geographic |
Bawden Ice Rise Buttress |
geographic_facet |
Bawden Ice Rise Buttress |
genre |
Antarc* Antarctica Ice Sheet Ice Shelf Ice Shelves The Cryosphere |
genre_facet |
Antarc* Antarctica Ice Sheet Ice Shelf Ice Shelves The Cryosphere |
op_source |
The Cryosphere, Vol 7, Iss 6, Pp 1931-1947 (2013) |
op_relation |
http://www.the-cryosphere.net/7/1931/2013/tc-7-1931-2013.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-7-1931-2013 https://doaj.org/article/d7f9ce2590bb4f81863e552dfae31e08 |
op_doi |
https://doi.org/10.5194/tc-7-1931-2013 |
container_title |
The Cryosphere |
container_volume |
7 |
container_issue |
6 |
container_start_page |
1931 |
op_container_end_page |
1947 |
_version_ |
1766262143610519552 |